Studies on a fluorescence spectroscopic detection technique for photo-generated free radicals of fenvalerate^#

Abstract

A novel approach to detect short-lived free radicals was investigated by combining a radical-trapping technique with highly sensitive and selective fluorescence spectroscopy. The generated benzyl radicals formed via homolytic cleavage of the ester linkage by photochemical decarboxylation of fenvalerate could be trapped by a nitroxide spin label possessing a primary amino group. The instantaneous and quantitative reaction of the resultant trapping adducts with fluorescamine, a specific fluorescent probe precursor for a primary amino compound, formed the highly fluorescent derivatives suitable for fluorescence-detection HPLC. The chemical structures of the fluorescence derivatives were identified by LC/MS spectrometry.